(function (window,document) {
    function GVerify(options) {
        //创建一个图形验证码对象，接受options对象为参数
        this.options = { //默认options参数值
            id:"", //容器ID
            canvasId:"verifyCanvas",    //canvas的ID
            width:"100",    //默认Canvas宽度
            height:"30",    //默认Canvas高度
            type:"blend",   //图形验证码默认类型blend;数字字母混合类型、number、letter(纯字母)
            code:"",
            isLine:false,   //是否开启干扰线，默认关闭
            isPoint:true,  //是否开启干扰点，默认开启
        }
        if(Object.prototype.toString.call(options)=="[object Object]"){ //判断传入参数类型
            for(var i in options){  //根据传入的参数，修改默认参数值
                this.options[i]=options[i];
            }
        }else{
            this.options.id=options;
        }
        this.options.numArr="0,1,2,3,4,5,6,7,8,9".split(",");
        this.options.letterArr=getAllLetter();
        this._init();
        this.refresh();
    }
    GVerify.prototype={
        version:'1.0.0',
        _init:function () {
            var con = document.getElementById(this.options.id);
            var canvas = document.createElement("canvas");
            this.options.width = con.offsetWidth>0?con.offsetWidth:"100";
            this.options.height = con.offsetHeight>0?con.offsetHeight:"30";
            canvas.id = this.options.canvasId;
            canvas.width = this.options.width;
            canvas.height = this.options.height;
            canvas.style.cursor = "pointer";
            canvas.innerHTML = "您的浏览器的版本不支持canvas";
            con.appendChild(canvas);
            var parent = this;
            canvas.onclick = function () {
                parent.refresh();
            }
        },
        refresh:function () {   //生成验证码
            this.options.code = "";
            var canvas = document.getElementById(this.options.canvasId);
            if(canvas.getContext){
                var ctx = canvas.getContext('2d');
            }
            ctx.textBaseline = "middle";
            ctx.fillStyle = radomColor(180,200);
            ctx.fillRect(0,0,this.options.width,this.options.height);
            if(this.options.type=="blend"){
                var txtArr = this.options.numArr.concat(this.options.letterArr);
            }else if(this.options.type=="number"){
                var txtArr = this.options.numArr;
            }else{
                var txtArr = this.options.letterArr;
            }
            for(var i = 1;i <= 4;i++){
                var txt = txtArr[radomNum(0,txtArr.length)];
                this.options.code += txt;
                ctx.font = radomNum(this.options.height/1.5,this.options.height)+'px SimHei'; //随机生成字体大小
                ctx.shadowOffsetX = radomNum(-3,3);
                ctx.shadowOffsetY = radomNum(-3,3);
                ctx.shadowBlur = radomNum(-3,3);
                ctx.shadowColor = "rgba(0,00,255,0.9)";
                var x = this.options.width/5 * i;
                var y = this.options.height/2;
                var deg = radomNum(-30,30);
                //设置旋转的角度和坐标的原点
                ctx.translate(x,y);
                ctx.rotate(deg * Math.PI / 180);
                ctx.fillText(txt,0,0);
                //恢复旋转的角度和坐标的原点
                ctx.rotate(-deg * Math.PI / 180);
                ctx.translate(-x,-y);
            }

            /**绘制干扰线**/
            if(this.options.isLine) {
                for (var i = 0; i < 4; i++) {
                    ctx.strokeStyle = radomColor(40, 180);
                    ctx.beginPath();
                    ctx.moveTo(radomNum(0, this.options.width), radomNum(0, this.options.height));
                    ctx.lineTo(radomNum(0, this.options.width), radomNum(0, this.options.height));
                    ctx.stroke();
                }
            }
            /**绘制干扰点**/
            if(this.options.isPoint) {
                for (var i = 0; i < this.options.width / 4; i++) {
                    ctx.fillStyle = radomColor(0, 255);
                    ctx.beginPath();
                    ctx.arc(radomNum(0, this.options.width), radomNum(0, this.options.height), 1, 0, 2 * Math.PI);
                    ctx.fill();
                }
            }
        },
        /**验证验证码**/
        validate:function (code) {
            var code = code.toLowerCase();
            var v_code = this.options.code.toLowerCase();
            return code == v_code;
        }
    }

    /**生成字母数组**/
    function getAllLetter() {
        var letterStr = "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
        return letterStr.split(",");
    }

    /**生成一个随机数**/
    function radomNum(min,max) {
        return Math.floor(Math.random()*(max-min)+min);
    }

    /**生成一个随机色**/
    function radomColor(min,max) {
        var r = radomNum(min,max);
        var g = radomNum(min,max);
        var b = radomNum(min,max);
        return "rgb(" + r + "," + g + "," + b + ")";
    }
    window.GVerify = GVerify;
})(window,document);